<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>
    div{
      width: 200px;
      height: 100px;
      background: #000;
      transform: skew(0, 10deg);
    }
    /* 
      skew(x, y)

      skewX()
      skewY()

      变形
        如果写一个正值，则是x轴逆时针旋转形成的新左边根据坐标轴标出对应的点形成的新图形
    
     */
  
  </style>
</head>
<body>
  <div></div>  
</body>
</html>